1. Field of the Invention
The invention relates to a technique that determines the main object characterizing an image, as well as a technique that adjusts the picture quality of the image data.
2. Description of the Related Art
The picture quality of digital image data produced by digital still cameras and the like can be adjusted as desired after photographs have been taken. Users can adjust picture quality using retouching software, for example. Meanwhile, because accurate adjustment of picture quality requires experience and familiarity, various techniques have been proposed for automatically adjusting picture quality using standard values without the need for user input.
However, in automatic picture quality adjusting techniques, picture quality is adjusted on the assumption that the main object characterizing the image has been correctly determined, and the erroneous determination of the main object can thus result in poor picture quality. It is therefore important to properly analyze the characteristics of the image data, such as determining what the main object characterizing the image is, in techniques for automatically adjusting picture quality of image data, and there is a need for a technique to accurately determine the main object.
Furthermore, in automatic picture quality adjusting techniques, such determinations are made across the board, without taking into consideration subtle differences in the main object characterizing the image, and a standardized picture quality adjusting process is carried out on the main object that has been determined. It is therefore inherently impossible to carry out a picture quality adjusting process that takes advantage of the subtle characteristics of the main object, and it is not always possible to output a more attractive main object. There is thus a need for a picture quality adjusting technique that is more responsive to variations in main objects.